The attack vectors for exploitation are through IPv4 and IPv6 packets using the following protocols and ports:

HTTP using TCP port 80

HTTPS using TCP port 443

This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2013-3384.

IronPort Spam Quarantine Denial of Service Vulnerability: This vulnerability can be exploited remotely without authentication and without end-user interaction. Successful exploitation of this vulnerability could result in a denial of service (DoS) condition. Repeated attempts to exploit this vulnerability could result in a sustained DoS condition.

The attack vectors for exploitation are through IPv4 and IPv6 packets using the following protocols and ports:

TCP port 82

TCP port 83

This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2013-3386.

Management GUI Denial of Service Vulnerability: This vulnerability can be exploited remotely without authentication and without end-user interaction. Successful exploitation of this vulnerability could result in a denial of service (DoS) condition. Repeated attempts to exploit this vulnerability could result in a sustained DoS condition.

The attack vectors for exploitation are through IPv4 and IPv6 packets using the following protocols and ports:

HTTP using TCP port 80

HTTPS using TCP port 443

This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2013-3385.

There are multiple vulnerabilities in Cisco Content Security Management Appliance. The following subsections summarize these vulnerabilities:

Web Framework Authenticated Command Injection Vulnerability: This vulnerability can be exploited remotely with authentication and with end-user interaction. Successful exploitation of this vulnerability could allow arbitrary code execution.

The attack vectors for exploitation are through IPv4 packets using the following protocols and ports:

HTTP using TCP port 80

HTTPS using TCP port 443

This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2013-3384.

IronPort Spam Quarantine Denial of Service Vulnerability: This vulnerability can be exploited remotely without authentication and without end-user interaction. Successful exploitation of this vulnerability could result in a denial of service (DoS) condition. Repeated attempts to exploit this vulnerability could result in a sustained DoS condition.

The attack vectors for exploitation are through IPv4 packets using the following protocols and ports:

TCP port 82

TCP port 83

This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2013-3386.

Management GUI Denial of Service Vulnerability: This vulnerability can be exploited remotely without authentication and without end-user interaction. Successful exploitation of this vulnerability could result in a denial of service (DoS) condition. Repeated attempts to exploit this vulnerability could result in a sustained DoS condition.

The attack vectors for exploitation are through IPv4 packets using the following protocols and ports:

HTTP using TCP port 80

HTTPS using TCP port 443

This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2013-3385.

There are multiple vulnerabilities in Cisco Web Security Appliance. The following subsections summarize these vulnerabilities:

Authenticated Command Injection Vulnerabilities: These vulnerabilities can be exploited remotely with authentication and with end-user interaction. Successful exploitation of these vulnerabilities could allow arbitrary code execution.

The attack vectors for exploitation are through IPv4 packets using the following protocols and ports:

HTTP using TCP port 8080

HTTPS using TCP port 8443

These vulnerabilities have been assigned Common Vulnerabilities and Exposures (CVE) identifiers CVE-2013-3383 and CVE-2013-3384.

Management GUI Denial of Service Vulnerability: This vulnerability can be exploited remotely without authentication and without end-user interaction. Successful exploitation of this vulnerability could result in a denial of service (DoS) condition. Repeated attempts to exploit this vulnerability could result in a sustained DoS condition.

The attack vectors for exploitation are through IPv4 packets using the following protocols and ports:

HTTP using TCP port 8080

HTTPS using TCP port 8443

This vulnerability has been assigned Common Vulnerabilities and Exposures (CVE) identifier CVE-2013-3385.

Mitigation Technique Overview

Cisco devices provide several countermeasures for these vulnerabilities. Administrators are advised to consider these protection methods to be general security best practices for infrastructure devices and the traffic that transits the network. This section of the document provides an overview of these techniques.

This protection mechanism filters and drops packets that are attempting to exploit these vulnerabilities.

Effective exploit prevention can also be provided by the Cisco ASA 5500 Series Adaptive Security Appliance, Cisco Catalyst 6500 Series ASA Services Module (ASASM), and the Firewall Services Module (FWSM) for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers using tACLs.

The Cisco Security Manager can also provide visibility through incidents, queries, and event reporting.

Risk Management

Organizations are advised to follow their standard risk evaluation and mitigation processes to determine the potential impact of this vulnerability. Triage refers to sorting projects and prioritizing efforts that are most likely to be successful. Cisco has provided documents that can help organizations develop a risk-based triage capability for their information security teams. Risk Triage for Security Vulnerability Announcements and Risk Triage and Prototyping can help organizations develop repeatable security evaluation and response processes.

Caution:The effectiveness of any mitigation technique depends on specific customer situations such as product mix, network topology, traffic behavior, and organizational mission. As with any configuration change, evaluate the impact of this configuration prior to applying the change.

Specific information about mitigation and identification is available for these devices:

Mitigation: Transit Access Control Lists

To protect the network from traffic that enters the network at ingress access points, which may include Internet connection points, partner and supplier connection points, or VPN connection points, administrators are advised to deploy transit access control lists (tACLs) to perform policy enforcement. Administrators can construct a tACL by explicitly permitting only authorized traffic to enter the network at ingress access points or permitting authorized traffic to transit the network in accordance with existing security policies and configurations. A tACL workaround cannot provide complete protection against these vulnerabilities when the attack originates from a trusted source address.

The tACL policy denies unauthorized HTTP and HTTPS on TCP ports 80 and 443 along with TCP ports 82, 83, 8080, and 8443 over IPv4 and IPv6 packets that are sent to affected devices. In the following example, 192.168.60.0/24 and 2001:DB8:1:60::/64 represent the IP address space that is used by the affected devices, and the hosts at 192.168.100.1 and 2001:DB8::100:1 are considered trusted sources that require access to the affected devices. Care should be taken to allow required traffic for routing and administrative access prior to denying all unauthorized traffic.

Note that filtering with an interface access list will elicit the transmission of ICMP unreachable messages back to the source of the filtered traffic. Generating these messages could have the undesired effect of increasing CPU utilization on the device. In Cisco IOS Software, ICMP unreachable generation is limited to one packet every 500 milliseconds by default. ICMP unreachable message generation can be disabled using the interface configuration commandsno ip unreachables and no ipv6 unreachables. ICMP unreachable rate limiting can be changed from the default using the global configuration commandsip icmp rate-limit unreachableinterval-in-ms and ipv6 icmp error-intervalinterval-in-ms.

Identification: Transit Access Control Lists

After the administrator applies the tACL to an interface, show ip access-lists and show ipv6 access-list commands will identify the number of HTTP and HTTPS on TCP ports 80 and 443 along with TCP ports 82 and 83 over IPv4 and IPv6 packets that have been filtered. Administrators are advised to investigate filtered packets to determine whether they are attempts to exploit these vulnerabilities. Example output for show ip access-lists 150 and show ipv6 access-list IPv6-Transit-ACL-Policy follows:

Administrators can use Embedded Event Manager to provide instrumentation when specific conditions are met, such as ACE counter hits. The Cisco Security white paper Embedded Event Manager in a Security Context provides additional details about how to use this feature.

Identification: Access List Logging

The log and log-input access control list (ACL) option will cause packets that match specific ACEs to be logged. The log-input option enables logging of the ingress interface in addition to the packet source and destination IP addresses and ports.

Caution: Access control list logging can be very CPU intensive and must be used with extreme caution. Factors that drive the CPU impact of ACL logging are log generation, log transmission, and process switching to forward packets that match log-enabled ACEs.

The CPU impact from ACL logging can be addressed in hardware on the Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers with Supervisor Engine 720 or Supervisor Engine 32 using optimized ACL logging.

Administrators can configure Cisco IOS NetFlow on Cisco IOS routers and
switches to aid in the identification of IPv4 traffic flows that may be
attempts to exploit these vulnerabilities. Administrators are advised to
investigate flows to determine whether they are attempts to exploit these
vulnerabilities or whether they are legitimate traffic flows.

Administrators can configure Cisco IOS NetFlow on Cisco IOS routers and
switches to aid in the identification of IPv6 traffic flows that may be
attempts to exploit the vulnerabilities that are described in this document.
Administrators are advised to investigate flows to determine whether they are
attempts to exploit these vulnerabilities or whether they are legitimate
traffic flows.

The following output is from a Cisco IOS device running Cisco IOS Software
12.4 mainline train. The command syntax will vary for different Cisco IOS
Software trains.

Introduced in Cisco IOS Software Releases 12.2(31)SB2 and 12.4(9)T, Cisco
IOS Flexible NetFlow improves original Cisco NetFlow by adding the capability
to customize the traffic analysis parameters for the administrator's specific
requirements. Original Cisco NetFlow uses a fixed seven tuples of IP
information to identify a flow, whereas Cisco IOS Flexible NetFlow allows the
flow to be user defined. It facilitates the creation of more complex
configurations for traffic analysis and data export by using reusable
configuration components.

The following example output is from a Cisco IOS device that is running a
version of Cisco IOS Software in the 15.1T train. Although the
syntax will be almost identical for the 12.4T and 15.0 trains, it may vary
slightly depending on the actual Cisco IOS release being used. In the following
configuration, Cisco IOS Flexible NetFlow will collect information on interface
GigabitEthernet0/0 for incoming IPv4 flows based on source IPv4 address, as
defined by the match ipv4 source address key field statement.
Cisco IOS Flexible NetFlow will also include nonkey field information about
source and destination IPv4 addresses, protocol, ports (if present), ingress
and egress interfaces, and packets per flow.

To only view the
HTTP and HTTPS packets
on TCP ports 80 and 443 along with TCP ports 82, 83, 8080, and 8443 use the show flow monitor
FLOW-MONITOR-ipv4 cache format table | include IPV4 DST ADDR
|_(80|82|83|443|8080|8443)_.*_06_ command to display the related
NetFlow records.

The following example output is from a Cisco IOS device that is running a
version of Cisco IOS Software in the 15.1T train. Although the
syntax will be almost identical for the 12.4T and 15.0 trains, it may vary
slightly depending on the actual Cisco IOS release being used. In the following
configuration, Cisco IOS Flexible NetFlow will collect information on interface
GigabitEthernet0/0 for incoming IPv6 flows based on the source IPv6 address, as
defined by the match ipv6 source address key field statement.
Cisco IOS Flexible NetFlow will also include nonkey field information about
source and destination IPv6 addresses, protocol, ports (if present), ingress
and egress interfaces, and packets per flow.

Mitigation: Transit Access Control Lists

To protect the network from traffic that enters the network at ingress
access points, which may include Internet connection points, partner and
supplier connection points, or VPN connection points, administrators are
advised to deploy tACLs to perform policy enforcement. Administrators can
construct a tACL by explicitly permitting only authorized traffic to enter the
network at ingress access points or permitting authorized traffic to transit
the network in accordance with existing security policies and configurations. A
tACL workaround cannot provide complete protection against these
vulnerabilities when the attack originates from a trusted source address.

The tACL policy denies unauthorized HTTP and HTTPS on TCP ports 80 and 443 along with TCP ports 82, 83, 8080, and 8443 over IPv4 and IPv6 packets that are sent to affected devices. In the following example,
192.168.60.0/24 and 2001:DB8:1:60::/64 represent the IP address space that is
used by the affected devices, and the hosts at 192.168.100.1 and
2001:DB8::100:1 are considered trusted sources that require access to the
affected devices. Care should be taken to allow required traffic for routing
and administrative access prior to denying all unauthorized traffic.

Identification: Transit Access Control Lists

After the tACL has been applied to an interface, administrators can use the
show access-list command to identify the number of HTTP and HTTPS packets on
TCP ports 80 and 443 and TCP packets on ports 82 and 83 over IPv4 and IPv6 that have been filtered. Administrators are
advised to investigate filtered packets to determine whether they are attempts
to exploit these vulnerabilities. Example output for show access-list
tACL-Policy and show access-list IPv6-tACL-Policy
follows:

In the preceding example, access list IPv6-tACL-Policy has dropped
the following packets received from an untrusted host or network:

39HTTP packets on TCP port
80 for ACE line 7

32 packets on TCP port
82 for ACE line 8

43 packets on TCP port
83 for ACE line 9

123HTTPS packets on TCP port
443 for ACE line 10

90 packets on TCP port 8080 for ACE line 11

87 packets on TCP port 8443 for ACE line 12

In addition, syslog message 106023 can provide valuable
information, which includes the source and destination IP address, the source
and destination port numbers, and the IP protocol for the denied packet.

In the following example, the show logging | grepregex command extracts syslog messages from the logging buffer on the
firewall. These messages provide additional information about denied packets
that could indicate potential attempts to exploit the vulnerabilities that are
described in this document. It is possible to use different regular expressions
with the grep keyword to search for specific data in the
logged messages.

In the preceding example, the messages logged for the tACL
tACL-Policy and IPv6-tACL-Policy show HTTP and HTTPS packets for TCP ports 80 and 443 and packets for TCP ports 82, 83, 8080, and 8443 sent to
the address block assigned to affected
devices.

Identification: Cisco Security Manager

Cisco Security Manager, Event Viewer

Beginning in software version 4.0, Cisco Security Manager can collect
syslogs from Cisco firewalls and provides the Event
Viewer, which can query for events that are related to the vulnerabilities that
are described in this document.

Using the following filters in the Firewall Denied Events
predefined view in the Event Viewer provides all captured Cisco firewall access
list deny syslog messages that could indicate potential
attempts to exploit the vulnerabilities that are described in this document.

Use the Destination event filter to filter network objects that contain
the IP address space that is used by the affected devices (for example,
IPv4 address range 192.168.60.0/24 and IPv6 address range
2001:DB8:1:60::/64)

Use the Destination Service event filter to filter objects that contain TCP ports 80, 82, 83, 443, 8080, and 8443

An Event Type ID filter can be used with the Firewall Denied
Events predefined view in the Event Viewer to filter the syslog IDs
shown in the following list to provide all captured Cisco firewall
deny syslog messages that could indicate potential attempts to
exploit the vulnerabilities that are described in this document:

ASA-4-106023 (ACL deny)

For more information about Cisco Security Manager Events, refer to the Filtering
and Querying Events section of the Cisco Security Manager User Guide.

Cisco Security Manager Report Manager

In the Report Manager, the Top Services report can be used with the
following configuration to generate a report of events that indicate potential
attempts to exploit the vulnerabilities that are described in this document:

Use the Destination IP network filter to filter network objects that
contain the IP address space that is used by the affected devices (for
example, IPv4 address range 192.168.60.0/24 and IPv6 address range
2001:DB8:1:60::/64)

Set an action of Deny on the Criteria settings page

Identification: Event Management System Partner Events

Cisco works with industry-leading Security Information and Event Management
(SIEM) companies through the Cisco
Developer Network. This partnership helps Cisco deliver validated and tested SIEM
systems that address business concerns such as long-term log archiving and
forensics, heterogeneous event correlation, and advanced compliance reporting.
Security Information and Event Management partner products can be leveraged to
collect events from Cisco devices and then query the collected events for the
incidents created by deny syslog
messages from firewalls that could indicate potential attempts to exploit the
vulnerabilities that are described in this document. The queries can be made by
Sig ID and Syslog ID as shown in the following list:

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